Note 3 - Age Analysis of Past Due Loans and Nonaccrual Loans (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015	Mar. 31, 2015
Commercial and Agricultural Portfolio Segment [Member] \| Commercial [Member] \| Financing Receivables, 30-89 Days Past Due [Member]
Accruing loans past due	$ 286	$ 491
Commercial and Agricultural Portfolio Segment [Member] \| Commercial [Member]
Accruing loans past due	286	491
Nonaccrual loans	529	577
Current loans	44,300	46,714
Loans and Leases Receivable, Gross	45,115	47,782	$ 51,774
Commercial and Agricultural Portfolio Segment [Member] \| Agricultural [Member] \| Financing Receivables, 30-89 Days Past Due [Member]
Accruing loans past due	777	71
Commercial and Agricultural Portfolio Segment [Member] \| Agricultural [Member]
Accruing loans past due	777	71
Nonaccrual loans	193	178
Current loans	17,592	18,944
Loans and Leases Receivable, Gross	18,562	19,193	19,188
Real Estate Portfolio Segment [Member] \| Commercial [Member] \| Financing Receivables, 30-89 Days Past Due [Member]
Accruing loans past due	5,385	6,031
Real Estate Portfolio Segment [Member] \| Commercial [Member]
Accruing loans past due	5,385	6,031
Nonaccrual loans	6,755	7,565
Current loans	335,232	332,666
Loans and Leases Receivable, Gross	347,372	346,262	341,845
Real Estate Portfolio Segment [Member] \| Commercial Construction [Member] \| Financing Receivables, 30-89 Days Past Due [Member]
Accruing loans past due	177	90
Real Estate Portfolio Segment [Member] \| Commercial Construction [Member]
Accruing loans past due	177	90
Nonaccrual loans	228	1,643
Current loans	35,565	38,374
Loans and Leases Receivable, Gross	35,970	40,107	48,611
Real Estate Portfolio Segment [Member] \| Residential Construction [Member]
Current loans	9,849	9,413
Loans and Leases Receivable, Gross	9,849	9,413	10,030
Real Estate Portfolio Segment [Member] \| Residential [Member] \| Financing Receivables, 30-89 Days Past Due [Member]
Accruing loans past due	2,199	3,683
Real Estate Portfolio Segment [Member] \| Residential [Member]
Accruing loans past due	2,199	3,683
Nonaccrual loans	2,874	3,164
Current loans	190,606	190,155
Loans and Leases Receivable, Gross	195,679	197,002	202,878
Real Estate Portfolio Segment [Member] \| Farmland [Member] \| Financing Receivables, 30-89 Days Past Due [Member]
Accruing loans past due	191	123
Real Estate Portfolio Segment [Member] \| Farmland [Member]
Accruing loans past due	191	123
Nonaccrual loans	1,327	1,103
Current loans	64,767	60,554
Loans and Leases Receivable, Gross	66,285	61,780	51,572
Consumer and Other Portfolio Segment [Member] \| Consumer [Member] \| Financing Receivables, 30-89 Days Past Due [Member]
Accruing loans past due	223	470
Consumer and Other Portfolio Segment [Member] \| Consumer [Member] \| Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Accruing loans past due	8	8
Consumer and Other Portfolio Segment [Member] \| Consumer [Member]
Accruing loans past due	231	478
Nonaccrual loans	195	178
Current loans	19,235	19,949
Loans and Leases Receivable, Gross	19,661	20,605	21,705
Consumer and Other Portfolio Segment [Member] \| Other [Member]
Current loans	15,768	16,492
Loans and Leases Receivable, Gross	15,768	16,492	6,031
Financing Receivables, 30-89 Days Past Due [Member]
Accruing loans past due	9,238	10,959
Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Accruing loans past due	8	8
Accruing loans past due	9,246	10,967
Nonaccrual loans	12,101	14,408
Current loans	732,914	733,261
Loans and Leases Receivable, Gross	$ 754,261	$ 758,636	$ 753,634

Financing receivables that are current.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 7A
-URI http://asc.fasb.org/extlink&oid=66008989&loc=SL6953401-111524

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- Definition

Recorded investment in financing receivables that are on nonaccrual status as of the balance sheet date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Recorded Investment
-URI http://asc.fasb.org/extlink&oid=65880944

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 7
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=66008989&loc=d3e5111-111524

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+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Recorded Investment
-URI http://asc.fasb.org/extlink&oid=65880944

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 7A
-URI http://asc.fasb.org/extlink&oid=66008989&loc=SL6953401-111524

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+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=65884687&loc=d3e4428-111522

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